An integrated change propagation scheduling approach for product design

A process simulation based method for scheduling product design change propagation

Propagation path optimization of product attribute design changes based on Petri Net fusion ant colony algorithm

Engineering Change Risk Assessment: Quantitative and qualitative change characterization

Nowadays, companies are developing more and more collaborative projects, and hence the need to exchange data with many partners, contractors, subcontractors, suppliers, and customers. So, to establish successful collaborations, they must ensure the relevance, coherence, and especially the security of exchanged data. But the Computer-Aided Design (CAD) systems still have gaps that need to be corrected in order to improve the productivity of the design process: they offer few solutions to maintain data consistency within the digital model. Adding to that poor management of changes, the user has to manage the consequences of each change manually. This research explores the role of mates’ assembly, as defined in CAD systems, as a key to maintaining the links between parts in the assembly. In this work, we propose the CAD Assembly Management Model that is based on reference elements, in order to maintain mates between CAD entities when a part is modified by a partner and then reinserted into the assembly CAD, and then propagate changes.

In optimizing the propagation paths of automotive product design changes, we applied the complex network theory to automotive product structure modeling and established a directed weighted auto part network model. In this model, we defined the parts as the nodes, the physical connections between the parts as the edges, and the impacts of change propagation as the weights of the edges. According to the characteristics of change propagation, we constructed a multiobjective optimization model that simultaneously considered the development time, development cost, and change risk. Using a multiobjective particle swarm optimization (MOPSO) algorithm, we solved the model and obtained the Pareto set of optimal solutions, which provided a basis for designers to choose the optimal design change plan. We conducted the multiobjective optimization of the air-conditioning system design change propagation path in a car model to verify the feasibility and effectiveness of the method.

Product design tasks in the upstream and downstream stages are often interdependent in engineering design processes. When design changes propagate from the upstream to the downstream, or vice versa, design tasks in different stages affect each other. Then solving the relevant design problems has to be repeated if the designer cannot find an acceptable solution to satisfy both downstream and upstream design requirements. In this paper, those design task connections with the interdependent nature or phenomena are referred to as design change propagation couplings and the analysis of the coupling is presented. Two types of coupling morphology named concurrent coupling and sequential coupling are identified. A theoretical method as well as a software system to solve such propagation couplings is developed. A design case of the feeding servo system on a numerical controlled machine tool is used to demonstrate the application of the software.

This paper starts with a brief introduction of computer-aided product innovation design technology, and then expounds the application of computer-aided product design technology in computer-aided innovation in detail. Then it expounds the hardware design of computer-aided product innovation system; Then it analyzes the application of knowledge resources in the process of computer-aided product innovation design, including the comprehensive utilization of knowledge resources in computer-aided product innovation design and the obstacles to the application of knowledge resources in computer-aided product innovation design. This paper starts with a brief introduction of computer-aided product innovation design technology, and then expounds the application of computer-aided product design technology in computer-aided innovation in detail. Then it analyzes the application of knowledge resources in the process of computer-aided product innovation design, including the comprehensive utilization of knowledge resources in computer-aided product innovation design and the obstacles to the application of knowledge resources in computer-aided product innovation design. Finally, the paper analyzes the product innovation design based on computer-aided innovation technology, including the problems in the process of product innovation design, how to solve the problems encountered in the process of product design, the generation of solutions to the problems in the process of product design and the process of value analysis in product innovation design, in order to make product design stakeholders pay attention to the research and specific research and development process of computer-aided product innovation design system.

Data exchange between different computer-aided design (CAD) systems is a major problem inhibiting information integration in collaborative engineering environments. Existing CAD data format standards such as STEP and IGES enable geometric data exchange. However, they ignore construction history, features, constraints, and other parametric-based CAD data. As a result, they are inadequate for supporting modification, extension and other important higher-level functionality when accessing an imported CAD model from another CAD system. Achieving such higher-level functionality therefore often requires a time-consuming, error-prone, tedious process of manually recreating the model in the target CAD system. Based on techniques adapted from programming language research, this paper presents an approach to exchanging parametric data between CAD systems using formally-defined conversion semantics. We have demonstrated the utility of our approach by developing a prototype implementation that automates the conversion of 2D sketches between two popular CAD systems: Pro/ENGINEER and SolidWorks. We present examples showing that our approach is able to accurately convert parametric CAD data even in cases where models were constructed using operations from the source CAD system that have no direct counterpart in the target CAD system. Although the case study focuses on 2D interoperability, our approach provides formal foundations for supporting 3D and semantic interoperability between CAD systems.

Environment-oriented product development and costs reduction often go hand in hand. The Environmental Design Cost model [Willems (1995)] has been developed to give companies the possibility to calculate the present and future costs of various environment-friendly changes in product designs. This model calculates the changes in the production costs and the changes in the present value of future end-of-life processing costs.

Design changes are frequently encountered in the product development process. The complexity of the design changes is multiplied when the product design involves multiple engineering disciplines. Very often, a simple change in one part may propagate to its neighboring parts, therefore, affects the entire product assembly. Both parts and assembly must be regenerated for a physically valid product model, at the same time, the regenerated product model must meet designer’s expectations. When a product is being developed in a Concurrent Design and Manufacturing (CDM) environment, the design changes are usually implemented first by altering geometry of the product represented in computer-aided design (CAD) solid models. If the product solid model is not parameterized properly, the changes in geometry often lead to invalid parts or assembly. At the part level, the changes may yield a solid model with invalid geometric features if it is not properly parameterized. In this case, the entire product assembly is in vain. Even when individual parts of the product are regenerated correctly, parts may still penetrate to their neighboring parts or leave excessive gaps among them, if the solid model is not properly parameterized at the assembly level. In this paper, solid modeling and assembly techniques implemented in two major CAD tools, Pro/ENGINEER and SolidWorks, will be discussed. A set of guidelines will be proposed for the designers to parameterize the solid models in order to capture the design intents more effectively in the product virtual mockup. These guidelines at both part and assembly levels will support designers to successfully conduct product design in the CDM environment. A number of examples, including a slider-crank mechanism and its crankshaft, a single-piston airplane engine and its components, as well as a number of simpler parts are presented to illustrate and demonstrate the parameterization method and guidelines proposed for both Pro/ENGINEER and SolidWorks.

This paper describes computer-aided design for quality — a new, cost-effective methodology for designing high-quality, manufacturable products using computer-aided design (CAD) systems. Traditionally, CAD systems have been used to simulate a producT's characteristics for a given set of values for the design parameters. Thus, designers could study the effects of design choices on a producT's quality before production started. Recent advances in computer hardware technology have given CAD systems increasingly complex and accurate simulation capabilities, permitting simultaneous examination of the effects of changes in many design parameters. But CADQ goes a step further. It provides powerful, statistical, model-fitting methods and optimization techniques that extend the traditional use of CAD systems. Given a set of quality-performance measures, a designer now can interactively pursue a producT's optimal design, while considering manufacturing constraints and characteristics of the customers' environment. Through a case study, we show the application of CADQ to integrated-circuit design.

Processes are very important for the success within many business fields. They define the proper application of methods, technologies, tools, and company structures in order to reach business goals. Not only manufacturing processes have to be defined from the start point to their end, also other processes like product development processes need a proper description to gain success. For example in automotive industries complex product development processes are necessary and defined prior to product development. Over the last decades several product modeling languages have been developed moving to object oriented modeling languages, such as UML, but the used process modeling languages are still procedural. The paradigm shift caused by object oriented description within product modeling languages has to be transferred to process modeling languages. This paper describes an object oriented approach for process modeling, referred to as PML and its application to a complex product development and production process for integrated sheet metal design of higher order bifurcations. Using UML as a starting point an object oriented process modeling method is differentiated. The basic concepts which are needed for process modeling are put into an object oriented context and are explained. The paper gives an outlook, what can be achieved by the new approach.

An evaluation of the relationship between management practices and computer aided design technology

Aim: The aims of this study were to (i) understand what adolescents (and their parents) identify as positive and negative experiences with technology for engaging in physical activity (PA) when living with type 1 diabetes (T1D) and (ii) identify possible future design considerations for supporting or enabling technologies for this population. Methods: Nine online collaborative workshops (n = 25 people) were held over a month with participants who were either adolescents attending with (n = 22) or without (n = 3, aged 16 and over) parents. Each workshop involved (1) a training activity, (2) a design task involving describing a good day vs. a bad day, and (3) a design task asking people to consider future design changes for technology to support them in engaging with physical activity. Results: The following key themes emerged from the first design task: (1) Wearable factors; (2) Social acceptance & identity; (3) Negative emotions; (4) Glycaemic stability offers positive emotions and PA Enjoyment; and (5) Presence, preparation & prevention. The second design task identified the following additional key themes: (6) Improve attachment experiences; (7) Connected devices reduce user burden; (8) Improve accuracy; (9) Personalisation of devices; (10) Funding and policy changes – health equity. Conclusion: Technology can reduce the burden and improve PA support, but there are still gaps in how these technologies can be better designed to consider the psychosocial and emotional factors of both adolescents and their parents as co-users.

Computer integrated design systems will require an improved understanding of the engineering design process, including formalized notions of (1) the structure of the process, (2) the design tasks that need to be performed, and (3) the information required to carry out these tasks. An organizational model for the structural engineering design process, termed themultilevel selection-development (MSD) model, has been outlined in a recent paper. The current paper continues development of the MSD model by providing more detailed descriptions of the specific design tasks that must be carried out. The MSD model is briefly reviewed, and a simple example is presented. The design tasks are then classified and described.